Apparatus for the proportioning and control of fluid flow



May 1%0 Qua/r f/zy of liquid whiz/9 ll? disc/[aged f/Irouglr one of flu? outlets Filed Dec. 25, 1946 Quantity Pressure Difference Pressure D/Tfire/rve BEfluaen Compartment: Between Com arfmenzs 334 MmM partment 6 and at an identical height in comthe overflows I2 and I0, respectively, of the dividing apparatus, the pressures in such spaces will correspond with those at the aforesaid levels in the bath.

- The dividing apparatus is supplied with water from tank 44 through conduit 9. Tank 44 is kept Jup to the mark by means of a pump 46 and an overflow, connected to the pump tank 48. The difierence (c) in height between the overflows Iiland I2 in the dividing apparatus is equal to the difference in depth of immersion of the open partment 4. All liquid introduced into the apparatus will, therefore, flow over at I2 and will be discharged at I!) through the ascending conduit and overflow I3. When, however, the pressure in compartment 4 is lowered, the liquid will rise therein. As soon as the pressure difference between 4 and 6 amounts to 0 mm. liquid, the level in 4 will have reached the top of overflow IE3, Thus,

when the pressure difference is exactly 0 mm., liquid-entering the apparatus will be divided and equal quantities of liquid will flow over at Ill and at I2, and will be discharged from the apparatus through the ascending conduits 22 and 26, respectively, and the overflows II and I3, respectively, and I8 and i9.

If new the pressure in 6 is raised a little, and in consequence, the pressure difference between the compartments is caused to exceed 0 mm., the level in 6 sinks below the top of overflow i2, and all liquid flows away through overflow iii. Thus, 0 is the limiting value of the pressure difierence, above which all liquid flows over at It and II, respectively, and below which all liquid flows over at I2 and I3, respectively.

Figure 4 is a flow sheet of an embodiment of the present process for keeping constant the specific weight of a bath for the separation of coal and rock according to specific weight. In this figure, 24 indicates a suspension bath, the specific weight of which has to be kept accurately constant. To keep the bath up to the mark, a continuous supply of suspension is provided at 25. The specific ends of the dipping tubes 33 and 36, multiplied by the-desired specific weight of the bath in 24.

If the specific weight is right, the pressure difference in the spaces above the overflows I0 and I2 will be equal to 0 mm. water column, and equal quantities of Water will pass through I!) and I2. Water, flowing over at I2, flows through conduit 20, overflow I3 and conduit I9 to pump tank 48,

weight of this supply suspension may vary more or less, (care however being taken that it always higher than the desired specific weight) and increases arising therefrom in the specific weight of the bath are compensated by introducing water at I8. vThe quantity of water, if-any, which must be introduced into the bath at I8 must, in consequence, depend upon the specific weight ofthe bath. If the latter is only a little above or a little below that which is desired, only a little or no water must be supplied. In case the diflerence is great, considerable water has to be supplied.

The present invention provides the desired flow control by using the specific weight of the bath as a regulating factor. Thus, the specific weight is converted into a pressure'factor by providing two conduits 3i] and 32 which open into the bath at different depths, both conduits communicating on the other side with the proportion unit or space 2-. The pressure difference (d) at the levels where the immersed ends of the dipping tubes 3% and 36 open is a measure for the specific weight. The tubes and 32 are connected to a compressed air supply tube 38. By means of valves ii and 42, the air supply can be adjusted to let some air escape from the dipping tubes 34 and 36, so that it can be ensured that the pressure in the conduits 30 and 32 is exactly the same as the pressure in the bath at the levels where the dipping tubes open therein. Since the conduits 38 and 32 com- 'municate with the pipes I6 and I4, respectively,

I which in turn communicate with the spaces above and recirculates.

When the specific weight of the bath gets too low, the pressure difierence between S t and 36 will decrease, as will also the pressure difl'erence in the spaces over the overflows Iii and I2 in the dividing apparatus; in consequence, the liquid level will sink below the top edge of overflow Ii], and water will flow away over I2 only, so that water is no longer supplied to the bath 23. When, however, the specific weight in the bath gets too high, the pressure difference between as and 36 and also in the spaces over It and I2 in the dividing apparatus will rise, the liquid level sinks below the top edge of I2 and all water flows through i0 to the bath. Thus, the suspension i diluted until the desired specific weight i again reached.

'By varying the construction of the regulating apparatus, the volume of the dead space over the overflows I0 and I2, the volume of the air conduits 3i and 32, the quantity of air supplied at 38, and the length of the overflow edges, etc., the proportionlng apparatus is made more Or less sensitive, i. e., made to provide control as shown in Figures 1 or 2.

I claim:

1. Apparatus for proportioning a liquid supply, comprising two compartment communicating with each other below the liquid level therein, each compartment being provided with an overflow outlet for the liquid, and means for regulating the pressure of the atmosphere over the liquids in both compartments, one of the two compartments being provided with an inlet for the liquid supply.

2. In apparatus for proportioning a liquid supply, a pair of compartments adapted to be connected to the liquid supply to be proportioned, the two compartments communicating with each other below the liquid level therein, a pair of conduits respectively extending to a closed space above the liquid level of the respective compartments, said conduits being adapted to be connected to respectively diiierent sources of pressure, each of said compartments being provided with an overflow outlet, the overflow outlet of one compartment being vertically spaced from that of the other compartment.

3. In combination, a container for a first liquid the specific gravity of which may vary from a desired value, a pair of compartments for a second liquid having such specific gravity that it is capable of restoring'said first liquid in said container to a desired value, the two compartments communicating with each other below the liquid level therein, a first conduit extending from a given depth in said first liquid to a point above 5 the liquid level in the first of said compartments, a second conduit extending from a less depth in said first liquid to a point above the liquid level in the second of said compartments, each conduit opening to a closed space above the liquid level in the corresponding compartment, a source of pressure communicating with both of said conduits, a source of said second liquid in communication with said compartments, each of said compartments being provided with an overflow out- 10 let, the overflow outlet of one compartment being vertically spaced from that of the other compartment by a distance depending upon the specific gravity at which said first liquid is to be maintained, the overflow outlet of one of said compartments being in communication with said first liquid container.

6 4. The combination described in claim 3, wherein the overflow outlet of the second of said compartments is in communication with said first liquid container.

JACOB DE KONING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,332,953 Tromp Oct. 26, 1943 2,382,853 Brammer Aug. 14, 1945 

